The present invention relates generally to press machines and more particularly to a linkage operated press.
Presses for stamping and piercing sheet metal are well known. Conventional presses typically are driven by a large hydraulic piston, vertically oriented screws rotated by electric motors, or crankshafts, in combination with toggle linkage mechanisms. Examples of these conventional presses are disclosed in the following U.S. Pat. No. 7,810,368 entitled “Multi-Mode Hammering Machine” which issued to Rusch on Oct. 12, 2010; U.S. Pat. No. 6,510,786 entitled “Hydromechanical Press Drive” which issued to Harsch on Jan. 28, 2003; U.S. Pat. No. 4,920,782 entitled “Press Drive” which issued to Hellwig on May 1, 1990; and U.S. Pat. No. 3,763,690 entitled “Press Brake Ram Leveling” which issued to Kirincic et al. on Oct. 9, 1973. All of these patents are incorporated by reference herein.
These conventional presses, however, suffer various deficiencies. For example, they open and close too slowly. Furthermore, traditional hydraulically and motor driven presses often have jerky opening and closing movements which reduces durability. Prior crankshaft and sector gear mechanisms also require custom, and therefore expensive, parts.
In accordance with the present invention, a press machine includes at least one actuator and at least one linkage to open and close a ram. Another aspect employs a sheet metal-working punch mounted to the ram. A fluid-powered piston drives a carriage coupled to a linkage in another aspect of the present machine. In still another aspect, at least a majority of an actuator is located externally to an outside surface of a stationary structure within which a ram is located. Yet a further aspect both opens and closes a ram with a unidirection movement of an actuator. Methods of operating a press are also provided.
The present linkage press machine is advantageous over conventional presses. For example, the present machine operates faster and smoother. Furthermore, standard components can be used to move the present ram, as compared to traditional devices, thereby reducing the expense of manufacturing the present machine. Additional advantages and features of the present machine will become apparent from the following description and appended claims.